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Biomedical subjects

C A Price

Publications and source records attributed to C A Price.

At least 55 records · Page 3Linked to original sources
PubMed1995

Superovulatory treatments do not alter pulsatile LH secretion in ovariectomized cattle.

Previous work has shown a suppressive effect of superovulatory treatments on pulsatile LH release in cattle. This study tested the hypothesis that this suppression may be caused, at least in part, by a direct effect of commercial gonadotropin preparations on the hypothalamus/pituitary gland. Crossbred Holstein heifers, ovariectomized 20 d before the start of the experiment, received 6 injections of FSH (50 mg Folltropin) at 12-h intervals (n = 6); a single injection of 2500 IU eCG followed by 5 injections of sterile saline at 12-h intervals (n = 6); or 6 injections of saline at 12-h intervals (controls; n = 5). Blood samples were taken every 10 min for 8 h the day before and 3 d after the beginning of treatment to assess LH pulsatility. At the end of these sampling periods, a bolus injection of GnRH (7 ng/kg) was given to assess pituitary responsiveness. There were no effects of the superovulatory drugs on mean LH concentrations, nor on LH pulse frequency or amplitude (P > 0.05). The pituitary response to GnRH was significantly elevated in eCG- but not FSH-treated animals (paired t test; P < 0.05). These data demonstrate that superovulatory preparations do not suppress pulsatile LH secretion independently of the ovaries in cattle.

Journal Article↗
PubMed1995

Effects of short-term exposure to hydroxyflutamide in utero on the development of the reproductive tract in male mice.

To determine if and when short-term ablation of androgen action compromises the development of the male reproductive tract in mice, the androgen receptor antagonist hydroxyflutamide was administered orally to pregnant FVB/N mice and the reproductive tracts of the male offspring were examined when adult. Hydroxyflutamide (30 mg per day) for 5 days from day 11 to day 15 of gestation caused hypospadias in all male progeny. However, testis weights, seminal vesicle weights, and serum testosterone levels were not affected (p > 0.05) but caput-corpus epididymal weights were 15% lower than controls (p < 0.02). Shorter periods of treatment that included day 14 or 15 caused hypospadias, but treatments that did not include days 14 and 15 did not (p < 0.002). Hydroxyflutamide (30 mg, once or twice daily for 2 consecutive days) between days 15 and 20 of gestation demonstrated that androgen ablation on days 15 & 16 caused hypospadias, absence of prostate, and scrotal location of the seminal vesicles with abdominal testes (p < 0.05). Males exposed later in pregnancy had prostates, but the weights were reduced (p < 0.001); testes were scrotal and seminal vesicles were abdominal; caput-corpus epididymal weights were 15-30% lower than controls (p < 0.05), but the tubule contained large numbers of spermatozoa. Furthermore, testis weights, serum testosterone, and the response of the testis to a human chorionic gonadotropin (hCG) challenge in vitro were not compromised by hydroxyflutamide, and seminiferous tubules exhibited normal spermatogenesis. When males that had been exposed to hydroxyflutamide on days 13 & 14, 15 & 16, 17 & 18 and 19 & 20 were housed with sexually mature females, pregnancies resulted only from the day 19 & 20 treatment group. Thus, there are long-term effects caused by short-term blockade of androgen action at critical times during pregnancy and such effects could result in the inability to impregnate, irrespective of any externally visible indications of developmental anomalies.

Androgen Antagonists↗
PubMed1995

Comparison of hormonal and histological changes during follicular growth, as measured by ultrasonography, in cattle.

The aim of the study was to compare histological and endocrinological indices of ovarian follicle health in cattle with monitoring of follicle growth and regression by ultrasound imaging in vivo. Ultrasound scanning was performed daily. Follicles were obtained at ovariectomy; follicular fluid was collected for assay, and the degree of atresia was assessed histologically. Histological atresia was correlated with growth patterns when anovulatory growing and regressing follicles were compared (P < 0.05), but was not different between growing and static follicles. Oestradiol concentrations were lower in static than in growing follicles, although the difference was not significant (35 +/- 7 versus 260 +/- 120 ng ml-1; P < 0.08), and were significantly lower in regressing follicles (7 +/- 5 ng ml-1; P < 0.05). Oestradiol concentrations were significantly lower in histologically atretic than in nonatretic follicles (16 +/- 8 versus 282 +/- 132 ng ml-1; P < 0.05), but were not different between nonatretic and early atretic follicles (P > 0.05). There was a significant negative correlation between oestradiol concentration and the number of days the follicle was visible by ultrasound (r = -0.71; P < 0.001). Concentrations of progesterone in follicular fluid were correlated with the number of days the follicles were detected (r = 0.61; P < 0.01) and were higher in regressing than in growing follicles (122 +/- 71 versus 48 +/- 13 ng ml-1; P < 0.05) but not significantly higher in atretic compared with nonatretic follicles (129 +/- 102 versus 53 +/- 15 ng ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Chromoplasts.

Explore the source record for details and available documents.

Carotenoids↗
PubMed1994

Evidence that testosterone and follicular fluid do not interact in the control of FSH secretion in rams.

The hypothesis that testosterone and inhibin interact in the control of FSH secretion in rams was tested. Adult rams were castrated and were simultaneously given testosterone implants and 3-times daily sc injections of 0, 0.4, 0.8 or 1.6 ml charcoal-treated bovine follicular fluid (bFF). After 1 wk, the implants were removed, and the bFF injections continued as before. Blood samples were taken daily for mean LH, FSH and testosterone concentrations, and every 10 min for 12 h in the presence and in the absence of testosterone for assessment of pulsatile LH release. The bFF specifically inhibited FSH secretion from rat pituitary cells in culture. In the presence of testosterone, there were no main effects of bFF on mean plasma FSH or LH concentrations, nor were these values different from their pre-treatment means (P>0.05). Treatment with bFF did not affect LH pulse frequency or amplitude, but the number of rams showing LH pulses was reduced in the 0.8 and 1.6-ml dose groups (P<0.05). Removal of testosterone increased (P<0.05) both gonadotropins. In the absence of testosterone, no main effect of bFF on mean LH or FSH concentrations was observed, although the 1.6-ml dose suppressed the postcastration rise of both LH and FSH. These data suggest that inhibin does not interact with testosterone and that a physiological level of testosterone is sufficient for the regulation of FSH secretion in adult rams.

Journal Article↗
PubMed1994

Decreased pulsatile LH secretion in heifers superovulated with eCG or FSH.

This study was designed to test the hypothesis that treatment with super-ovulatory drugs suppresses endogenous pulsatile LH secretion. Heifers (n=5/group) were superovulated with eCG (2500 IU) or FSH (equivalent to 400 mg NIH-FSH-P1), starting on Day 10 of the estrous cycle, and were injected with prostaglandin F(2alpha) on Day 12 to induce luteolysis. Control cows were injected only with prostaglandin. Frequent blood samples were taken during luteolysis (6 to 14 h after PG administration) for assay of plasma LH, estradiol, progesterone, testosterone and androstenedione. The LH pulse frequency in eCG-treated cows was significantly lower than that in control cows (2.4 +/- 0.4 & 6.4 +/- 0.4 pulses/8 h, respectively; P<0.05), and plasma progesterone (3.4 +/- 0.4 vs 1.8 +/- 0.1 ng/ml, for treated and control heifers, respectively; P<0.05) and estradiol concentrations (25.9 +/- 4.3 & 4.3 +/- 0.4 pg/ml, for treated and control heifers, respectively; P<0.05) were higher compared with those of the controls. No LH pulses were detected in FSH-treated cows, and mean LH concentrations were significantly lower than those in the controls (0.3 +/- 0.1 & 0.8 +/- 0.1, respectively; P<0.05). This suppression of LH was associated with an increase in estradiol (9.5 +/- 1.4 pg/ml; P<0.05 compared with controls) but not in progesterone concentrations (2.1 +/- 0.2 ng/ml; P>0.05 compared to controls). Both superovulatory protocols increased the ovulation rate (21.6 +/- 3.9 and 23.0 +/- 4.2, for eCG and FSH groups, respectively; P>0.05). These data demonstrate that super-ovulatory treatments decrease LH pulse frequency during the follicular phase of the treatment cycle. This could be explained by increased steroid secretion in the eCG-treated heifers but not in FSH-treated animals.

Journal Article↗
PubMed1994

Acute renal failure: a sequelae of sepsis.

Acute renal failure in the critically ill patient may have a wide range of clinical presentations and necessitate numerous nursing interventions. This article reviews the etiologies, pathophysiology, and diagnoses related to acute kidney dysfunction with a particular emphasis on sequelae related to sepsis. Additionally, the nursing care for managing patients with acute renal failure with the available renal replacement modalities is discussed.

Acute Kidney Injury↗
PubMed1994

Physical assessment for patients receiving therapeutic plasma exchange.

As more nephrology programs include therapeutic plasma exchange (TPE), nephrology nurses must be prepared to treat the variety of indications for which TPE is prescribed. The purpose of this article is to assist nephrology nurses as they incorporate TPE into their scope of practice. The article addresses a total body systems approach to the physical assessment that is completed for all patients. Following the total physical assessment, specific areas of assessment are discussed as they relate to clinical diseases or syndromes for which TPE is the treatment of choice.

Humans↗
PubMed1994

A history of dental polymers.

The disadvantages of the use of vulcanite as a denture base material prompted the development of a wide range of thermoplastic polymers as alternatives to vulcanite. Heat-cured acrylic resin materials are the most widely used polymeric denture base materials at present, but research into further improvements in denture base materials continues.

Acrylic Resins↗
PubMed1993

Occurrence of the chromoplast protein ChrA correlates with a fruit-color gene in Capsicum annuum.

Plant geneticists have determined that the color of ripe fruits of sweet peppers (Capsicum annuum L.) is determined by four genes: y, c1, c2 and cl. We have compared the electrophoretic behavior of chromoplast membrane proteins of seven varieties of C. annuum which differ in these genes. ChrA was detected only in the varieties that had a y+ genotype, and was not affected by variations in the other three genes. The identity of ChrA was verified by probing blots of SDS gels with antiserum to ChrA. The second known chromoplast-specific protein, ChrB, was found to be independent of all four genes. No proteins correlating with c1, c2 or cl were detected in either one- or two-dimensional gels.

Capsicum↗
PubMed1993

Patient selection committees: should they be reinstituted?

Chronic renal failure is no longer synonymous with death. Federal and state government funding for end stage renal disease (ESRD) services and advances in modern technology now make the prolongation of life possible for almost any individual with renal failure. However, the same medical devices and sources of funding that support renal replacement therapies have also contributed to the moral and ethical debates that surround these treatments. Discussions regarding quality of life, rehabilitation statistics, functional status data, prognosis, decision making protocol, and selection criteria provoke much controversy in the nephrology community and remind us of the "Death or God Committees" utilized in the pre-Medicare days to make decisions regarding access to dialysis treatments. In this issue of ANNA Journal, Marguerite Hartigan and Christy Price revisit the issue of selection criteria and explore the advantages and disadvantages of using established protocol to access the services of the ESRD Program and nephrology community.

Decision Making, Organizational↗
PubMed1993

Technical considerations of therapeutic plasma exchange as a nephrology nursing procedure.

In the past, therapeutic plasma exchange (TPE) has had limited appreciation and lacked acceptance as a treatment modality. Jokingly, it has been referred to as a procedure looking for a disease because of seemingly broad historical applications to practice. In current clinical practice, TPE has earned its place as an aggressive therapeutic modality for treating a wide spectrum of diseases and/or syndromes. The acceptance of TPE has coincided with changes in equipment, technology, and the emergence of highly qualified professionals involved in performing the treatments. This article will describe these variables related to nephrology nurses becoming more involved in the use of TPE.

Anticoagulants↗